something is definately wrong with my mustang's electrical system. I put in a new alternator a couple months ago...a new battery a couple months ago...a new starter...and i turned my car on for the first time in a week or two and it ran fine...i drove it on the freeway and everything. but when i got back home and turned it off and tried to turn it on again...it wouldn't start. didn't even crank. so i had the battery recharged and its back to normal. now i think its the voltage regulator but i'm not sure. could it be? and is it hard to rewire my car's electrical system if i'm a novice at electrical stuff? any help would really appreciated. thanks.
Posts: 303
Joined: 11/17/2003 From: Connecticut,United States Status: offline
Sounds like an alternator problem, but I wouldn't rule out the VR. I would test the voltage at the battery when the car is running. It should be between 13-14 volts. If it's lower, I would suspect the alternator is not charging correctly. For the extra 20bucks, I'd change the regulator too.
My car did the same thing. Here is what I did, new alt, new battery X2, new battery cables, pos, neg and starter, new voltage regulator.
Found out that the harness plug that connects to the regulator was making poor contact from years of oxidation and no clip to hold it in place. Put a meter on your car to see what your output is, and then jiggle the voltage regulator plug to see if your output increases. If it does, you found your problem.
Printable Version
voltage regulator? - 
